Identification of a Cys-motif Gene, TSP13, as a Putative Host Translation Inhibitory Factor in Plutella xylostella-Cotesia plutellae

Eunseong Kim,Yeongtae Kim,Yonggyun Kim 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

Translational control is a strategy for various viruses to manipulate their hosts to suppress any acute antiviral activity. Some cys-motif genes encoded in polydnaviruses or teratocytes act as host translation inhibitory factor (HTIF) to defend the host antiviral activity. A novel cys-motif gene, TSP13, was encoded in the genome of an endoparasitoid wasp, Cotesia plutellae. TSP13 consists of 129 amino acid residues with a predicted molecular weight of 13.987 kDa and pI value at 7.928. Genomic DNA region encoding open reading frame is interrupted with three introns. TSP13 was expressed in Plutella xylostella larvae parasitized by C. plutellae. C. plutellae bracovirus (CpBV) was purified and injected to nonparasitized P. xylostella. In the virus-injected P. xylostella, TSP13 was shown to be expressed by RT-PCR analysis. Thus, TSP13 was turned out to be encoded in the proviral CpBV genome. TSP13 was cloned into a eukaryotic expression vector, which was then used to infect Sf9 cells to transiently express TSP13. The synthesized TSP13 was detected in the culture broth. Purified TSP13 significantly inhibited cellular immune responses. Furthermore, TSP13 entered the target cells and was localized in the cytosol. This study reports a novel cys-motif gene, which is encoded in CpBV genome localized on chromosome(s) of C. plutellae and replicated to be encapsidated in the episomal viral particles during parasitization.

Purification of a Polydnaviral Gene, CpBV-ELP1, and Oral Insecticidal Activity

Eunseong Kim,Yonggyun Kim 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

Baculovirus expression system has been used to produce functional proteins of various eukaryotic genes. A polydnaviral gene, CpBV-ELP1, was cloned in an alpha-baculovirus, Autographa californica multiple nuclear polyhedral virus (AcNPV), and expressed in Sf9 cells. CpBV-ELP1 protein was released into the culture medium due to its signal peptide. The culture broth containing CpBV-ELP1 was collected and fractionated with different concentrations of ammonium sulfate. Most CpBV-ELP1 was precipitated in 25-100% ammonium sulfate. The precipitate proteins were separated with a size exclusion chromatography sieving 100 kDa size. CpBV-ELP1 was eluted after relatively high molecular weight protein peaks. The fractions rich in CpBV-ELP1 were collected and further fractionated with an anion exchange chromatography. The purified CpBV-ELP1 was toxic to both larvae of Plutella xylostella and Spodoptera exigua by oral test used as leaf dipping method. A lethal median concentrations (LC50) were 7.5 ㎍/mL (95% CI: 1.2-24.3 ㎍/mL) for 2nd instar larvae of P. xylostella and 4.4 ㎍/mL (95% CI: 1.9-8.4 ㎍/mL) for 3rd instar larvae of S. exigua. These results suggest that CpBV-ELP1 may be applied to develop novel transgenic crops.

Enhancement of Cry Toxicity by Ingestion of Bacterial Expressing dsRNA of β-integrin Subunit in Spodoptera exigua

Eunseong Kim,Younggyun Kim 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10

Double-stranded RNA(dsRNA) had been used to specitically suppress target gene expression at post-tanscription level. Injection of dsRNA to hemocoel is the most efficient to knockdown target mRNA. However, some insects have shown to be susceptible to feeding dsRNA. Spodoptera exigua was susceptible to dsRNA at oral treatment. Especially dsRNA specific to β-integrin was potent to survival of S.exigua larvae. This study advanced our dsRNA application technology by generating recombinant E.coli expressing dsRNA specific the β-integrin. A recombinant vector L4440 was constructed with a partial β-integrin gene under T7 RNA polymerase promoter. The recombinant vector was used to transform HT115 competent cells of E.coli. The transformed E.coli expressed the dsRNA. The production of dsRNA was proportional to the bacterial number. By feeding the recombinant E.coli, S.exigua underwent significant mortality. By adding E.coli expressing Cry1Ca Bt toxin to E.coli expressing dsRNA, S.exigua exhibited highly enhanced mortality. This study suggests a possibility to use a recombinant E.coli expressing dsRNA to control S.exigua.

Disintegration of midgut epithelial cells by oral feeding of a recombinant bacterium expressing dsRNA specific to integrin

Eunseong Kim,Youngjin Park,Younggyun Kim 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

Oral toxicity of double-stranded RNA (dsRNA) specific to integrin β1 subunit (SeINT) was known in a polyphagous insect pest, Spodoptera exigua. For an application of the dsRNA to control the insect pest, this study prepared a recombinant Escherichia coli expressing dsRNA specific to SeINT. The dsRNA expression was driven by T7 RNA polymerase overexpressed by an inducer in the transformed E. coli. The produced dsRNA amount was proportional to the number of the cultured bacteria. The bacteria gave a significant oral feeding mortality to S. exigua larvae with a significant reduction of the SeINT expression. The resulting insect mortality increased with the fed number of the bacteria. Pretreatment with a sonication to disrupt bacteria cell wall membrane significantly increased the insecticidal activity of the transformed bacteria. Compared to the control bacteria transformed by non-recombinant vector, the larvae fed the bacteria expressing dsRNA specific to SeINT suffered tissue damage in the midgut epithelium, which was characterized by a loose cell-cell contact and a significant cell death. The dsRNA-treated larvae were significantly more susceptible to a Cry toxin derived from Bacillus thuringinesis (Bt) than the larvae treated only with Cry toxin. This study demonstrates that a transformed bacterium expressing dsRNA specific to SeINT has a significant insecticidal activity by oral application against S. exigua and makes the target insects to be highly susceptible to Bt toxin.

Cytotoxicity of A Novel Oxidant Fumigation on Hemocytes of Plodia interpunctella and Other Insect Cell Lines

Sunil Kumar,Jeyeong Park,Eunseong Kim,Jahyun Na,Yong Shik Chun,Hyuk Kwon,Wook Kim,Yonggyun Kim 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10

A novel oxidant fumigation (NOF) has been considered as alternative fumigant to replace methyl bromide that is a serious ozone depleter. Its high oxidative activity has been used as a bleaching or sanitary agent. Though some reports an insecticidal activity of NOF, its insecticidal action is yet to be understood. This study was conducted with an observation of an insecticidal activity of NOF against Plodia interpunctella, which is a stored grain insect pest. Cytotoxicity test was performed by using MTT assay, NOF gave a significant cytotoxicity on both Sf9 cells and HiFive insect cell lines. Sf9 cells were higher susceptible (IC50 = 43.2+ 3.5 ppm) to chloride dioxide than HiFive cells (IC50 = 174.6 + 5.9 ppm). To understand its cytotoxic effect on P. interpunctella, the larval hemocytes were incubated in vitro with different doses of NOF for 40 min at room temperature. In a dose-dependent manner, NOF gave a significant toxicity to the hemocytes. When NOF was injected to larvae of P. interpunctella, it significantly reduced total hemocyte counts compared to control. These results indicate that NOF has cytotoxic effect against hemocytes of P. interpunctella. This hemolytic activity of NOF can be regarded as a lethal factor to the stored grain insect pest.

Gary Snyder as a Translator and Poet in Cold Mountain

Kim, Eunseong 한국동서비교문학학회 2004 동서 비교문학저널 Vol.0 No.10

Nature and Society in Early American Poetry

Kim Eunseong 한국중앙영어영문학회 2005 영어영문학연구 Vol.47 No.1

Since ancient times, nature as an object of projection has involved various interpretations and assumptions which have enabled nature to be endowed with diverse symbols and then to have a personal, social, and even theological correspondence with humans. This correspondence, in turn, has made people create various kinds of philosophy, literature, and tradition. The relation of literature to nature, therefore, has not consisted in the merely literary description of nature but in expressing changes in ideas, a criterion of value judgement, and national experience. This relation, therefore, is an essential means to understanding and criticism of society and politics. This aspect is, especially, important for understanding America and its people, who established and modified their identity within a comparatively brief historical period. In the early history of America, Puritanism, the philosophy of the Enlightenment, and Romanticism all made contributions in their own way to the formation of American culture and identity. In the progress of this formation, nature was an essential way of expressing the experiences of each period. This paper, therefore, aimed to describe a change of American views of nature and the correlation between this change and that of social and cultural attitudes through American poets of the early colonial periods to the late nineteenth century.

Constructing, Naturalizing, and Subjugating Nature into Human Discourse

Eunseong Kim 한국비평이론학회 2002 비평과이론 Vol.7 No.2

Synthesis and Gas Sensing Properties of ZnO Nanostructures

Kim, Hyojin,Hung, Nguyen Le,Ahn, Eunseong,Jung, Hooncheol,Kim, Dojin Korean Physical Society 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.6

Thin film transistors using preferentially grown semiconducting single-walled carbon nanotube networks by water-assisted plasma-enhanced chemical vapor deposition

Kim, Un Jeong,Lee, Eun Hong,Kim, Jong Min,Min, Yo-Sep,Kim, Eunseong,Park, Wanjun IOP Pub 2009 Nanotechnology Vol.20 No.29

<P>Nearly perfect semiconducting single-walled carbon nanotube random network thin film transistors were fabricated and their reproducible transport properties were investigated. The networked single-walled carbon nanotubes were directly grown by water-assisted plasma-enhanced chemical vapor deposition. Optical analysis confirmed that the nanotubes were mostly semiconductors without clear metallic resonances in both the Raman and the UV–vis–IR spectroscopy. The transistors made by the nanotube networks whose density was much larger than the percolation threshold also showed no metallic paths. Estimation based on the conductance change of semiconducting nanotubes in the SWNT network due to applied gate voltage difference (conductance difference for on and off state) indicated a preferential growth of semiconducting nanotubes with an advantage of water-assisted PECVD. The nanotube transistors showed 10<SUP>−5</SUP> of on/off ratio and ∼8 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> of field effect mobility. </P>